Devices used by children for play or educational purposes often require the use of hinges for opening and closing the devices. For example, a typical toy might include a hard molded plastic case formed to contain a wire spiral book. The case often has a front cover hinged to a back cover, with each cover containing electronic circuitry to interact with the book to help a child learn to read or solve math problems.
Due to the wire spiral that holds such books' pages together, a gap is generally formed between the front and rear covers of the case to allow the book to be stored in the case when closed and to lay flat when the case is opened. This gap creates a pinching hazard for small children, as fingers may be caught between the front and rear covers when opening or closing the molded plastic case.
The American Society for Testing and Materials (ASTM) has set a safety standard for such gaps in their standard consumer safety specifications on toy safety. According to the ASTM, toys having a gap or clearance along a hinge-line between a stationary portion and a movable portion must have a gap less than 3/16 inch or larger than 1/2 inch. Thus, there is a need for an apparatus for reducing the likelihood of pinching between two rigid, hinged covers and that meets the ASTM safety standard.